Non-specific immunosuppressive therapy of man is associated with considerable morbidity. Some regimens are superior to others. The New Zealand mice offer a convenient model for studying different drug regimens prior to study in patients. It would be even more desirable to treat patients in an immunologically more specific manner. Toward that end we have been treating New Zealand mice with activators of suppressor cells and with suppressor cells themselves. The autoimmune process in NZB mice can be markedly retarded by such specific immunosuppression. Soluble suppressor substances have been substituted for cells and found to be effective. If such a substance can be isolated and synthesized it might be useful for humans. Treatment of NZB/NZW mice with Ribavirin, a broad spectrum anti-viral durg, has been very effective. Renal deposits of immune complexes can be prevented. Such treatment is applicable to humans with SLE.